Behavioral Science: Schizophrenia 1 & 2 Flashcards
Schizophrenia general features
- psychosis is a hallmark symptom
- may present as alterations in sensory perceptions (hallucinations), abnormalities in thought content (delusions), of abnormalities in thought process/organization
illusion definition
misperception of real external stimuli
hallucination definition
sensory perceptions not generated by external stimuli
ideas of reference definition
false conviction that one is subject of attention by other people, feeling as though people are referring to you in their conversations
delusions definition
false beliefs not correctable by logic or reason, not based on simple ignorance, and not shared by culture
- MC delusions of persecution
loss of ego boundaries
not knowing where one’s mind and body end and those of another begin
alogia
lack of informative content in speech, poverty of speech
echolalia (clanging)
repeating statements of others/associating words by sounds, not meaning
thought blocking
abrupt halt in the train of thinking, often due to hallucinations
neologisms
inventing new words
circumstantiality
in responding to questions, one presents unnecessary add voluminous details ultimately arriving at an answer to the question
tangentiality
beginning a response in a logical fashion but then getting further and further away from the point, failing to answer the question initially posed
loose associations
loss of logical meaning between words or thoughts, when asked a question, illogically jumps from one subject to another
DSM5 criteria for schizophrenia
A. Characteristic symptoms: 2 or more of the following, each present for a significant portion of time during a 1 month period (less if successfully treated):
- delusions, hallucinations, grossly disorganized or catatonic behavior, negative symptoms, disorganized speech
B. Social/occupational dysfunction: one or more major areas of functioning are markedly below level achieved prior to onset
C. Duration: continuous signs for 6+ months, with at least 1 month of symptoms that meet criterion A and may include periods of prodromal or residual symptoms
D. schizoaffective and mood disorder exclusion
E. substance/medical condition exclusion
Positive symptoms
Additional to expected behavior
ex. delusions, hallucinations, agitation, talkativeness, thought disorder
- respond well to most traditional and atypical antipsychotic agents
Negative symptoms
Missing from expected behavior
ex. lack of motivation, social withdrawal, flattened affect, cognitive disturbances, poor grooming, impoverished speech
- sometimes better response with atypical antipsychotics
3 phases of schizophrenia
Prodromal, psychotic, residual
Prodromal phase
Prior to first psychotic break
- avoidance of social activities, quiet and passive or irritable, sudden interest in religion or philosophy, physical complaints, anxiety and depression
Psychotic phase
Loss of touch with reality
- Associated with positive symptoms
Residual phase
Period between psychotic episodes. In touch with reality, but doesn’t behave normally.
- Negative symptoms, peculiar thinking, eccentric behavior and withdrawal from social interactions
Genetics of schizophrenia
- twin studies support role of genetics
- advanced paternal age? –> de novo mutations in paternal germ cells
Gender differences in schizophrenia
- occurs equally in men and women
- onset: 15-25 years in men, 25-35 years in women
- women respond better to antipsychotics, but greater risk of tardive dyskinesia
tardive dyskinesia
- cumulative days of D2 receptor drug blockade can lead to permanent movement disorder, choreic movements
Environmental factors leading to schiz
- viral infection and exposure to drugs during development
- increased incidence when born in cold-weather month, possibly due to viral infxns?
- 3rd trimester maternal use of diuretics
- In adults, anti-NMDA receptor antibodies?
Neurological abnormalities in schiz
- Decreased use of glucose in prefrontal cortex (hypofrontality)
- lateral and 3rd ventricle enlargement
- loss of cerebral asymmetry
- decreased volume of hippocampus, amygdala, parahippocampal gyrus
- decreased alpha waves, increased theta and delta waves, epileptiform activity on EEG
- abnormal eye movement
What regions of the brain are hypoactive and hyperactive in schiz?
Hypoactive: dorsolateral PFC
Hyperactive: ventromedial PFC
Role of dopamine in schiz
Excessive DA activity in mesolimbic tract
- stimulants can cause psychosis by amplifying this tract
- negative symptoms may involve a diff abnormality, perhaps hypoactivity of mesocortical tract
- elevated levels of HOMOVANILLIC ACID (metabolite of DA) in bodily fluids of pts with schiz suggest inc. DA activity and use in CNS
Role of serotonin in schiz
Serotonin hyperativity
- hallucinogens which increase serotonin cause hallucinations and delusions
- atypical antipsychotics have anti-5HT2A receptor activity
Role of norepi in schiz
Possible hyperactivity
-paranoid subtype may have increased metabolites
Role of glutamate in schiz
- antagonists of NMDA receptors aggravate or create psychosis, agonists may relieve symptoms
NMDAR hypoactivity hypothesis
If NMDAR proteins are mutated, they become ineffective.
- If they sit on GABA interneurons between cortical GLU neuron and its secondary neuron, a loss of inhibition occurs in the secondary GLU allowing excessive firing and ultimately an increase in firing in the VTA, sending extra DA into the limbic system, causing psychosis
DDx of schiz
- psychotic disorder caused by medical condition
- manic phase of bipolar
- substance induced psychosis
- other psychotic disorders
Brief psychotic disorder
1-29 days schiz symptoms
Schizophreniform disorder
1 month-6 months schiz sx
schizoaffective disorder
schizophrenia + mania/depression
delusional disorder
delusions but no other schiz sx
shared psychotic disorder
one person is delusional and a second person develops the same delusion
Medication for schiz
- all effective antipsychotics block D2 receptors in mesolimbic DA path
- lifelong treatment
- typical and atypical antipsychotics
- low compliance due to unpleasant side effects and poor patient insight
Typical first generation antipsychotics
High potency: Haloperidol, Low potency: chlorpromazine
- high potency drugs better at binding and sticking to D2 receptors, may cause more side effects
Atypical second generation antipsychotics
- Block D2 receptors AND 5HT2a receptors
- first line agents due to fewer negative side effects
- 5HT2a blockade allows DA to flow more freely in the nigrostriatal path (where low DA causes parkinson-y sx)
Psychotherapy for schiz
- CBT to improve executive dysfunction, family therapy, Peer and Mentor support or social skills group
Prognosis with schiz
- downhill course in 90%
- often stabilizes in midlife w/ more negative symptoms predominating
- suicide is very common
Good prognostic indicators: female, older onset, married, good relationships, positive sx, few relapses, good employment
